The code which does the anonymization:
- discourse/app/services/user_anonymizer.rb at main · discourse/discourse · GitHub
- discourse/app/jobs/regular/anonymize_user.rb at main · discourse/discourse · GitHub
It will:
- Username is changed to:
anon#<random number> - password made random (and invalid)
- name removed or changed to username
- date of birth is removed
- title is removed
- avatar is removed
- optionally IP is anonymized
- emails is changed to
<username>@anonymized.invalid - location in profile is removed
- website in profile is removed
- bio is removed
- profile background is removed
- card background is removed
- custom user fields are removed
- SSO is cleared
- API keys are removed
- invites and emails are removed
As the username is changed, Discourse will try to replace the username is all posts.
Reversal is basically impossible, but user information can remain in individual posts.